I second McMaster-Carr. I’ve had great experiences with them. The only downside is that they don’t give you the price of shipping until after the order is completed and processed. They do this not to freak you out (although that can definitely happen) but because they charge exactly what the shipping company charges them and they update the order when the shipper gives them the bill based on size/weight of the total combined package.

I’ve used McMaster Carr too. In regards to shipping, I’ve found them to be very responsive to questions. I needed some 1/4” aluminum bar stock, and asked them for shipping estimates for 2 3-foot long pieces, or 1 6-foot long piece, and I had my answer within an hour or two. It was reasonable, I think to ship the 2 3-foot pieces of 1/4”x3” stock, it was around 8-10 bucks (domestic, though).

-- - The mightiest oak in the forest is just a little nut that held its ground.